Electrogeneration of H2O2 using a porous hydrophobic acetylene black cathode for electro-Fenton process

Abstract

The aim of this work is to prepare a hydrophobic cathode equipped with quite a few cracks for gas transfer, which can prepare H2O2 in the course of electro-Fenton process. Scanning electron microscopy (SEM) and optical digital microscope are used to characterize the morphology of electrode, and an electrochemical workstation (CHI660e) is used to carry out all electrochemical studies with a conventional three-electrode system. The results demonstrate that the porous electrode is conducive to gas transmission with these cracks which can avoid the formation of bubbles. Additionally, the reaction is almost not affected by the content of dissolved oxygen and the gas flow with this structure. Under the conditions of 300 mA/cm2 (current density), the H2O2 concentration is up to 14.4 mmol/L after 30 min electrolysis with current efficiency beyond 90%. Furthermore, the cathode is successfully applied to electro-Fenton process which reduced catalyst loading. The results indicate that total degradation of MO is observed at the first 10 min, and 81% of TOC can be removed when the dosage of catalyst is 0.4 mmol/L within 60 min.